The endangered Peruvian tern, known locally as the chirrío, is one of the world's smallest terns. Shown here in Peru's Paracas National Reserve, the seabird breeds in a thin strip of desert coastline in northern Chile and Peru. Its numbers have dwindled to as few as a thousand.

Photograph by Walter Romero

Jürgen Rottmann—a naturalist and ornithologist widely known as the David Attenborough of Chile—rehabilitates giants.

Almost 900 miles (1,450 kilometers) to the north of the animal rescue center lies a barren desert where Rottmann has cultivated a soft spot for a tiny creature—a seabird not much bigger than his hand—the elusive and very rare gaviotín chico, or Peruvian tern.

This tern has flourished for millennia along a thin strip of coastline from northern Chile to Peru where the Atacama Desert meets the zone of rich upwelling in the Pacific Ocean known as the Humboldt Current.

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The chirrío is particular in its nesting habits. Here, a tern incubates two eggs in a scrape of flat, rocky desert on the Mejillones Peninsula, the best site for them in Chile.

No more than a thousand of the birds may survive today, largely because of human activities in northern Chile's Mejillones Peninsula, a critical tern nesting area—and the site of a port complex, from which copper, vital to Chile's economy, is exported.

Rottmann and his field team have since spent years in the desert monitoring tern nesting sites, which are now clearly signed and demarcated; observing the habits of the terns and their predators; and even filling in pits and trenches made by the military in the terns' habitat.

They've also campaigned on local radio and television networks for protection of the terns and enlisted the participation of local schoolkids, councilmen, and industries, some of whose representatives now sit on the foundation's board. The foundation has been hailed as the first example in Chile of the public and private sectors joining forces to mitigate industrial impacts on natural habitat.

Speaking in the rehabilitation center, amid the flapping of condors' wings, Rottmann describes what's known—and not known—about the gaviotín chico and explains the challenge of protecting birds' nests in an increasingly altered landscape.

Why is this seabird—which has a range that includes both Chile and Peru—called the Peruvian tern?

The species was first described on the basis of a specimen from Peru, and so it became the "Peruvian tern." But the local name is chirrío, the greeting the terns make when meeting: a short and sharp chirrio, chirrio!—good to see you! If I asked the tern what it would like to be called, it wouldn't be Sterna lorata, gaviotín chico, or Peruvian tern. It would most certainly be chirrío!

What distinguishes the chirrío from other terns?

It's similar in color to the much more common South American tern but a lot smaller. It has several relatives. One is the Damara tern, which similarly nests on a desert coast—in Namibia. Another relative, the California least tern, inhabits the northern Pacific and nests in colonies in California and Mexico. The less gregarious chirrío nests only on the desert coasts of northern Chile and Peru, where it prefers to maintain sizable gaps between individual nests.

What prompted the chirrío's decline?

In 1995, an earthquake destroyed Chile's Antofagasta port, a major hub of copper export. Five years later, the construction of a new port commenced, this time in “Pampa Mejillones”, where the gaviotín chico has its nine—or fewer—principal nesting sites in Chile. With the new port came everything else, mostly associated with the mining sector—new roads, thermal power plants, refineries, pumping stations, desalination plants. [Mejillones is expected to become Chile's biggest seaport by 2030.]

An environmental impact assessment, which would have looked for ways of reducing, mitigating, or offsetting impacts, was not properly done because the underlying guiding regulations were lacking. In 2007, new regulations were enacted, and upon noticing declines, several different parties came together to act on behalf of the chirrío. They included the Union of Chilean Ornithologists, the mayor of Mejillones, and scientists from the University of Antofagasta.

Although I'd never before worked with industries, I was asked to lead. My background was in protected areas across Chile working with CONAF, Chile's equivalent of the U.S. Fish and Wildlife Service, also our forest service.

Our most important questions were: How many chirríos are left, how do they reproduce, and why are they declining?

To census them is difficult, as the surveys must be done everywhere simultaneously to get an accurate count. We now estimate fewer than 1,000 individuals in Chile, and we've banded 150 this year, despite the challenge of banding because of their extremely slender legs. [By banding individuals, Rottmann and his team can track the tern's movements, breeding success, and survivorship.]

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The chirrío lays one or two eggs per breeding season. Typically, only a single chick will fledge: Despite their good camouflage, the tiny chicks are vulnerable to predators such as foxes and stray dogs.

The primary threat is the loss of habitat in northern Chile because of the growth of cities and ports, expanding tourism infrastructure, military zones, industries, thermo-electric plants, power lines, and irrigation for agriculture. And off-road vehicles that circle around the beaches and desert.

Predators exacerbate human-caused declines. Terns' nesting sites are vulnerable to crows and raptors in the northern Pacific; jackals and hyenas in southern Africa; turkey vultures, caracaras, dogs in Chile; and foxes and feral cats in Peru.

We've generally seen an increase in depredation of indigenous wildlife by stray dogs, which have become more numerous in Mejillones because of strewn garbage and waste.

Nonlethal methods of protecting tern colonies include translocating predators or encircling nesting sites with fences. Another is to inject eggs with a vomiting agent that makes a predator averse—this is done in California.

But the chirrío chick weighs only 1.8 ounces [50 grams]—as much as about a quarter of an apple—and its eggs a mere eight to nine grams, so we can't inject enough poison into such a tiny egg to make a dog sick.

We've realized that Japanese quail eggs are of similar size, so we can use these—as well as electric eggs—to deter dogs and vultures from the real eggs.

Are other seabirds in the Mejillones region of Chile also declining?

No. The Inca tern[gaviotín monja] is actually increasing and expanding its range both to the north and south. But this tern nests in artificial places—even abandoned ships—and can therefore be considered to be a colonizer of human landscapes.

The gray gull[gaviota garuma] is also increasing. It flies high and at night—thus avoiding certain human activities—and goes to the desert once a day to feed its young, whereas the chirríos need small fishes, which they deliver one at a time, multiple times a day, to their nests.

What are chirríos' nesting needs?

They like to nest in flat desert not more than two miles [three kilometers] from the tide line. The grains of sand must be a certain size—not too small, as then the wind easily shifts them. These sites must afford space as the terns prefer to nest as far away from another pair as possible, allowing 200 to 300 meters [650 to 980 feet] between nests. This means that there are fewer than ten nests in each square kilometer. The availability of places with such precise characteristics is scarce. In Chile, the best place is Mejillones.

Despite being fussy, are they adaptable?

Yes. They've shown flexibility in their feeding habits—fishing and eating between docks, ships, and even swimmers. They're becoming accustomed to nesting near industries, train lines, roads, airports, and military bases.

We've realized that airports have become good refuges for them, as no human or canine trespassers are allowed. People often don't even know the terns live there, as they're so small and so fast. And the terns, despite their delicate size, don't seem to mind the noise from planes or helicopters—or even low-flying military jets.

I've seen big military jets fly directly over their nests, and the terns don't move a muscle. Other species—like flamingos that nest in the cordillera of Antofagasta—would abandon their nests if bothered by helicopters or low-flying planes.

I consider the chirrío to be agile and fast. Rarely would you see it get caught by a peregrine falcon, or see any other seabird make off with its fish.

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In the desolate Atacama Desert, this little seabird epitomizes resilience in nature—but it remains to be seen if it can survive in the face of unnatural threats.

Photograph by Walter Romero

What remains to be known about this tern?

One of the mysteries is where they spend the four months that they're not in Chile or Peru. From August to December they're in Chile, and from December to April in Paracas—the best place for them in Peru. But where they go in the austral autumn and winter is a real mystery.

After the last El Niño, many seabirds, including cormorants, boobies, and gulls—but not terns—starved. Around this time, about 200 miles [320 kilometers] off the Peruvian coast, the chirríos were seen perched on floating garbage. This attested to their ability to disperse far and wide.

We lack sufficient data on their diet but have recently discovered that squid and krill form part of it. We don't really know to what extent the foods on which they rely are being affected by the fishing industry.

We also don't know when they start reproducing, how long they live, and most important, if it would be possible to increase their population to get them off the Red List by conserving enough of their habitat in the long-term. [The IUCN Red List is an inventory of the conservation status of species worldwide.]

What is needed to save the terns?

We need more ways of protecting their habitat. One way would be to establish at least two clusters of reserves in northern Chile akin to the big national reserve in Paracas, Peru [1,293 square miles, or 3,349 square kilometers].

Outside the protected areas, we need for people and tourists to know and respect them. Off-road vehicles must avoid going around their breeding sites. People living near these sites must keep their dogs contained and keep their trash out of the desert. [Plastic residues in particular are lethal to many marine animals, especially seabirds.]

Perhaps counterintuitively, airports and military areas can help, as they are areas which the terns tolerate and use. Far from being areas for a specific human use, they can be shared with wildlife and become "multiple use areas."

We also need new regulations for the fishing sector and improved and intensified agreements with the Peruvian side [20 percent of the world's fish harvests are sourced from the Humboldt Current].

Crucially, we need to show the companies operating in the Mejillones area that the cost to them of helping protect this tern's nesting sites is small—especially for the bigger companies.

Can you describe a way in which you and the foundation have worked with industries in Mejillones?

We give seminars to the companies about the chirrío explaining that Mejillones is its main nesting site in Chile. We then invite them to see the nests and their proximity to the industrial area. At the nests, we explain how driving vehicles and other disturbances need to be curtailed during nesting time, even temporarily suspended altogether. We notify them of the arrival of the first pair and nest of the season, the first chicks, and share our other observations. The chirrío thus becomes part of the company.

What attitudinal shift would you like in conservation in northern Chile?

We've entered an era during which compatibility and adaptation from industry and conservation are needed.

It's important that the businesses legally obligated to protect the chirrío do not see this as one more rule, tax, or cost that is simply mandatory. I want them to see and experience it as something they willfully do and with joy. They can share in and feel part and pride of our efforts to allow these wonderful, tiny, but tough birds to continue to exist in our deserts.

Since 2008, because it's now a legal mandate, any construction, even if minor, must be accompanied by an impact assessment if suspected to affect the chirrío. Mitigation and compensation must be decided on. What better thing to do but work together under one NGO dedicated to protecting affected species and jointly improving the results and lowering the costs?

On top of that, it's important for the authorities to get involved and help strive for the best possible educational programs that instill pride and love for our natural heritage.

As for us conservationists, we need to know how to share the emotion and joy we feel. Everyone should be talking about our chirrío—that little guy who should not disappear, since in the desert plains of Mejillones, it symbolizes protection of nature and resilience in the harshest of conditions.